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@uiten taies. @anni Letters Patent No. 81,171, dated August-1s, 1868.

IMPROVEMENT IN SCREW-DRIVER ANDl GOUNTBRSINK.

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To ALL'WHOM 1T MAY ooNeERN:

Be it known that I, .PETER N. JAcoB'Us, of Flatbrookville, in the county of Sussex, and State of New Jersey, have inventedy a new and improved Screw-Driver and Countersink; and I do hereby declare that the following is a. full, clear, and exact description of the construction and operation ofthe same, referencebeing had to the accompanying-drawings, making a-part of this specification, in which- Figur'e 1 isalongitudinal vertical'section through line a: z of fig. 2.

- Figure 2 is an end view. v

Figure 3 is` an end view ofthe screw.. Y

The object of this invention is`to construct ascrew-driver in such a manner that it will grasp the screw by thehead, and hold it irmly'while inserting it into the wood or removing it therefrom, and, while inserting the screw, shall reamaway the wood around it, so as toform a countersink for its head.

To accomplish this object, Itinsert several (preferably three) griping-jaws in the end of the stock or tool, in suitable sockets provided for the purpose, constructing and arranging the jawsfm the end or head of the tool in such a manner that they are capable of sliding longitudinally, and as they are slid out,- their ends will diverge and drop the screw, while, as they are slid in, they will converge, and grasp its head firmly. The ends of the jaws which thus operate are bevelled o", and provided with cutters, which rearn away the wood under the head of the screw as' the head approachesl the surface of the wood, preparing a eountersink, in which the screw, when fully inserted, lies flush with the surface ofthe wood. i

In the drawings- A represents that part of the tool which holds the griping-jaws, the latter being shown at J JJ.

The jaws slide longitudinally in the part A, being held in place by a xed ring, R, on th-e extreme end thereof,'and by a sliding ring, S, which encircles the part A, and thc inner ends of thejaws JJ J.

The ring R may be, as seen in the drawings, simply a bulge on the end ofthe part A, provided with holes to receive and hold eaeh jaw.

Thejaws may he further heldy in position, and guided in their motions, by a pieccof metal, B, having three arms, and extendingaoross the end of the part A between the`jaws, as seening. 2.

The jaws are so shaped that as thus constructed and attached to thepart A, their outerk or griping ends will approach cach other when the jaws are slid inward in their sockets, and will rmly grasp and hold any object that may happen to be between,thcm,`releasingit, ofcourse, when slid outward again.

As'thus constructed, they are intended to grasp and hold the head of the screw while inserting the latter into or'removing it from the wood.

The head of the screw, as seen in iig. S, is notched on three sides, (or more, if intended to beused with a screw-driver having more than threejawsQand the inner side of eachjaw is bcvelled olfl from the centre, so that as thejaws cometogether they will nicely fit into the notches of the screw-head,rand'thus hold the screw much 'more firmly.`

The 'ends of thcjaws are he'velled off from their inner edge, as seen in fig. 1, and are provided with a sharp cutting-edge or shoulder, m, extendingfrom the pointat their extremity down to the corner e, and serving, as

the screw-driver comes in contact with the wood, to ream away the latter around the screwjust enough to countersink the head ofthe screw.

YIn working in softwood, the cutting-shoulders may not bc necessary, butthe jaws may be tapering and smooth. I l

With this instrument, the screw can he more easily and readily inserted'thanwithsuch as have been heretofore-employedifor the purpose.

It is not necessary to bore a hole to receive the screw, butthe latter can be grasped and forced into the wood without diilculty. Neither is it necessary to prepare a ceulntersinkl before inserting the screw, as the instrument performs that oliice without any additional effort, and-without any appreciable outlay of additional force on the part ofthe workman.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. A screwdriver, provided with sliding jaws, so operating that as they are slid inward they converge, and grasp the head of the screw firmly, and as they are slid out again, they diverge, and release it,

2. The combination of the part A, having the fixed ring R, the sliding ring S, the movable jaws J JJ, and the metallic piece B, substantially as described.

To the above specicaton'of my improvemcnt, 1 have signed my hand, this 5th day of June, 1868.

PETER N. JACOBUS.

Witnesses:

CEAS. A. PETTIT, SoLoN C. KEMoN. 

